Nanoscale Push-Push Dihydrophenanthrene Derivatives as Novel Fluorophores for Two-Photon-Excited Fluorescence

Clark Hull's drive-reduction theory, introduced in the 1940s and 1950s and often termed the "push theory" of motivation, provides a framework for understanding how biological and learned drives influence behavior. Hull suggested that motivation originates from the need to alleviate physiological tension caused by unmet biological necessities. The theory proposes that when a basic need, such as hunger or sleep, goes unfulfilled, it creates an internal imbalance. This imbalance, or...

Excitation-contraction coupling is a series of events that occur between generating an action potential and initiating a muscle contraction. It occurs at the triad, a structure found in skeletal muscle fibers that comprise a T-tubule and terminal cisternae of the sarcoplasmic reticulum on each side. These triads are visible in longitudinally sectioned muscle fibers. They are typically located at the A-I junction — the junction between the A and I bands of the sarcomere.
When an action...

The International System of Units or SI system, by international agreement, has fixed measurement units for seven fundamental properties: length, mass, time, temperature, electric current, amount of substance, and luminosity. These are called the SI base units.

In calculus, higher-order derivatives extend the idea of differentiation beyond the first derivative to capture successive rates of change. These derivatives provide detailed information about the behavior of functions and have important applications in both mathematics and physics. To illustrate these concepts, consider the example functionwhich serves as a useful case study for exploring higher derivatives.The first derivative represents the slope of the original function. The second...

DerivativesThe concept of instantaneous rate of change is fundamental in both mathematics and physics, particularly in describing how a moving object alters its position with respect to time. This rate is captured mathematically through the derivative of a function. The derivative at a point represents the slope of the tangent line to the curve of the function at that point and quantifies how the function’s output changes per infinitesimal change in input.Derivative of the Square Root...

A derivative quantifies how a function changes in response to variations in its input. It provides a localized rate of change, representing the slope of the tangent line to the function at any given point. When this process is applied systematically across the entire domain of the function, it yields a new function—the derivative function—which encodes the rate of change at every point. This concept is central to calculus and essential for understanding the behavior of dynamic...